Metal-working machine



Feb. 14, 1928.

A. KREBS METAL WORKING MACHINE Filed April 11, 1924 2 Sheets-Sheet 1 Feb. 14, 1928. V 4 v ,355,555

A.KREBS METAL WORKING MACHINE Filed Aprilll, 1924 2 Sheets-Sheet 2 air, raga Patented Feb 14 1 UNITED STATES 1 i 4mm:- xREn s 011 Boston, mssncnusm'rs; nssx'ouon 'ro 'rxm oxwnnn smvrcn coursing or nnwjzonx; m n, A conron s'uonor v I muswomxo" moms.

Application. and April. 11,. 1m. Serial m mm;

This invention reliites' tomachinesv for auttoma-tically moving and guiding a blow torch or other operative instrumentelity' along a predetermined path in accordancewith a. pattern'or templatei In the prior art, machines have been (16 j vi'sedl in. which a: blow" torch; is automatically moved by a rotating template follower" engaging the edge off a; fixed template When the relation: of the template andffollower is; such thatv it is necessary to raise the" follower to remove it from any particular part of the edge of thetemplate, or toplace it inposi-- tion. to follow the. template it has been necessar in prior machines to lift the objectionaoly large and cumbersome mechanism supporting the; follower or to make: some. other inconvenient: manipulation In a prior type of template followin .ma-

chine, a rotating; shaft automatically rives the follower along; one edge of a template while: a tracer: portiom slides alonp 'another similarly directed? ed'geofthe temp relation to the template of the driver and tracer portions of; the follower is such that continual sliding: takes place between the tracer and the en aged? portion? of the template, thus producing-fan undesirableamount of friction,v which not'only increases the load:

on themotor drivingthe template follower and "increases the strain-- and wearonathe'tem'gplate; but tend-s to: cause unevenness of op eration and. fluctuations; in the movementofthe follower along: the edge of the template.

Objects -of'the present. invention. are: to; overcome the above difliculties,.to provide; ef+- ficient: means for" lifting the follower from the template and" axially shifting the 01:-

lower with. minimum efiort and without in terfering: with; rotation of the? follower; to provide a. template follower-having separate rotating driverand tracer portions arranged to roll u on: thetempl'at'e with reduced: trio-- 7 tion, an igenerally to-improvermachinee of the kind; referred to;

lie conveniently displacedvaxially" without disturbing the driving mechanism. for rotati p cause the torch-to out the work material; 12

v tothecon .tourzof itheatemplateffii It'willtbe I r carriage 13" together thefbomplg.

" no i byi mny 50'- ing the. followeii The follower shaft" is provided with a rack witlig whicha :a p'inion '1 Inanother aspect; apparatus: of the} ate; The? moms convenientl Y- rotated ,ilt'ing al'ever-couple' ito itj referred; to is provided with for v for propelling the follower alongan edgeoff the templatetand having a tracer; shaft for rol'lin t along another similarly' directed edge o; "the template tobe 'traced thus affording?"anti-friction mechvnism for following contourof. the-template.

Other" features of the invention will beapparent from the detailedi'descriptionwhiclir follows;

For the purpose of illustrating. tho princi ples' of the' invention, specific modifications lower having. a power rotated driver of concrete embdiments are ShOWlI,lII. the nocompanying: drawing, whiclrr'-.--

Fig, 1: is a perspectiveview show-mgatems plate guided torch cutting machine;

Fig.2 is an elevation partly insection of the template following mechanism; and:

Figs. 3 and 4 are modifications of a: portion ofFig; 2. v

InFig: 1, a; blow torch- IOorother instrurnent'ality of well known construction;

having anozzle 11 for directing aflmover tically downwardtoward: the work material 125 is supported from'one end ofithocarrilge 13 having'wheels 14 rolling on. the horizontal floor of'carriage 15-provided with: the upturned v edges lfiffor guiding and restricting carriage,13 to incur mover ment' with respect to carria =15 Carriage- I5 is supported on wheels' l which in: turn are" supported on. the upper horizontal surfaces of 'rails 18' having? the upturned edges- 19 for guidingfwheelsl i andirestrictingcnriage l5 to" 111188 movement transverse to; that of carriage"1'3.,-' Motor20' is provided with a" worm gear-rotor shaft "21 moshing,

with the gear 22' rigidly 'coupled toflgear' 23 which in turn meshesrwith ar 24 a alongrthe line '28, corresponding lower" shaft25 and; torch Ill arowam for universal movement in; a horizo By providing an extended pairof rails 18 several carriages 15 together with the apparatus supported thereby may be simultaneously employed on the same rails to expedite the work on a large piece of work. material.

Fig. 2 shows in detail one arrangement of the template follower 25. The channel shaped template 27 is provided with the edge or face 30 to be traced .by the tracer portion 31 of shaft and is rovided with the oblique edge or face 32 to e engaged by' sleeve 34 to shaft 25. Sleeve .34 is fast at its upper end to gear 24 and is journalled in the bearing 25'. Upward axial movement of sleeve 34 in bearing 25' is revented by collar 37 made fast to the s eeve by set screw 38. Downward axial movement of sleeve 34 is prevented by gear 24 abutting on bearin 25'.

The cy indrical weight 39 surrounding shaft 25 and supported by the lower end 26, urges the shaft axially downward thereby bringing the driving portion 33 into close contact with the edge 32 of the template and producing a resultant force causing the tracer portion 31 of the shaft to engage close ly with the tem late edge 30. The frictional surface of the riving ortion 33 rolls along the ed e 32 and prope s shaft 25 along the edge of the template, the shaft bein guided by the tracer portion 3]. which fol ows the ed e of the template.

or the purpose of axially moving shaft 25 in sleeve 34 to chan e its relation with template 27, a series 0 alternate annular ridges 40 and recesses 41 are provided at the upper end of shaft 25, coaxial with the axis of the shaft, the spur gear 42 meshing with a the rack thus formed and being provided with the hand lever 43 fast thereto, by means of which. the gear is manually rotated on shaft 44 axially to displace shaft 25. Shaft 44 is 'ournalled in bracket 44 rigidly supporte from carriage 13. When handle 43 is raised gear 42 rotates in a clockwise direction thereby to lift the tracer portion .31 from the channel between the edges 30 and 32 of the template so that the follower may be moved from one part of the template to another, or lifted free of the template. Inasmuch as groove 36 is axiall directed, shaft 25 is free to move .axially in sleeve 34 without interfering with rotation of driving gear 24 and sleeve 34.

Rotation of shaft 25 causes the portion 33 to roll on the template while the portion 31 rotates in such a direction as to slide on the surface 30 with which it contacts, thus causing a certain amount of friction. While this form of template follower may be used satisfactorily in certain classes of work in spite of the friction, and particularly where it is desired to employ a relatively simple form of template follower mechanism, it is objectionable in certain other work and requires asomewhat complicated template. The arrangements shown in Figs. 3 and 4, which may be substituted for the lower portion of shaft 25, Fig. 2 substantially obviate the undesirable'friction between elements 30 and 31, and permit of using a much simpler form oftemplate than template 27.

In Fig. 3 the shaft 45 is provided with the frustro-conical driving portion 46 for engaging the upper left hand edge of the template strip 47. The frame or weight 48 within shaft 45 is journalled carries the upper thrust bearing late 49 having an annular raceway 50 or ball bearings. The lower thrust bearing plate 51 having a complementary raceway for the ball bearings rests on the shoulder 52 at the lower end of shaft 45. It will thus be seen that frame 48 is supported from shoulder 52 by ball bearings in the raceway 50 between the bearing plates 49 and 51, thus providing an antifriction bearing between the frame 48 and shaft.

The gear 53 fast to shaft 45 meshes with the gear 54 fast to shaft 55 having the tracer 56 for engaging the right hand surface of template 47. Rotation of shaft 45 causes the driving portion 46 of the shaft to propel the follower along template 47 at the same time causing rotation of shaft 55 by way of gears 53 and 54 and causing the tracer portion 56 to roll along the right hand surface or edge of template 47 Roller 56 is so proportioned in diameter with respect to gear 53 and 54 and driver 46 as-to have substantially the same peripheral speed at the point of contact with template 47 as the portion of the driver 46 engaging in contact with the template. Uniform and substantially frictionless movement of the follower along the template is thus provided.

In Fig.4 gear 57 fast to shaft 45 meshes with gear 58 fast to shaft 59 having the driver portion 60, corresponding to the driver portion 46 of Fig. 3, for supporting the frame 61 by thrust bearings similar to the thrust bearings 49 and 51 of Fig. 3. The shaft 62 and tracer portion 63, corresponding to shaft 55 and tracer 56 in Fig. 3, are rotated by gear 64 fast thereto and meshing with gear 65 fast to shaft 59. It will be noted that the axis of shaft 59 is offset from the axis of shaft 45 so that the axis of shaft 45 is disposed between the axes of Shafts 59 te'mplate. between the ad engaged by the follower ortions 60-.an 63, or ma intersect the e eof the templateen ge b the tracer. Diving to this disposl tion 0 the axis of shaft-45-ewithrespect to template 4.7, shaft 45 moreaccurately follows theconfiguration of the template, particularly at bends and at places where the direction of the template 7 changes. 1 Y I The action of the frustro-conical drivers 46 and 60 is similar to that of driver 33,

Fig. 2, in that the weight of frames 48 and 61, respectively, urges .the portions 46 and 60 downwardly, at the same time producing}.

resultant force drawing the tracers 56 and 6-3, respectively, closely'into contact withtemplate 47. Owing to the-disposition of the driver .and tracer portions of the fol.-

lower on opposite sides of the tem late, ro-

tation of frame 48, Fig. 3, and of rame 61, Fig. 4, with respect to the template 1s prevented.

Template 47 is of much simpler form than 7 template 27 and may be constructed from a strip of any substantial solid materlal, for example, metal, fiber or wood, and is preferably of such soft or flexible material that 1t may be readily formed into any desired shape for use as a template,'at the same time being capable of suitably retaining its shapeunder the stresses imposed by the template follower. The cleats 66, of solder or any other suitable material at the lower edge of each side of the strip, anchor the strip to a supporting base 67 to maintain the strip in its desired form when subjected to such stresses as are im osed b the template follower or by han ling o the template. If. desired, portions 47 and 67 of the template may be integrally formed as by welding, bolting or other. Fig. 2, may be.

casting, soldering, riveting, method. The template 2 secured to the base in the same manneras template 47 is secured to base 67. 'Whena template and base are cast, it is advantageous to employ relatively pliant material of low melting point such as lead, tin, solder, .l p

" a fixedtem aluminum, or other convenient and; cheap mate-rial which lends itself readil to ing to the desired shape when co d.

Iclaim:

1. In a machine of the character de scribed, a carria e arranged for universal movement in a p ane, a thermal instrumentality supported from said carriage, a shaft supported from said carriage on an axisnormal to said plane for followingthecontour of a template,means for rotating said shaft, said shaft being axially movable without interfering with said rotating means, a

and means for axially lifting said. shaft;- 2. In a machine of the character described, a carriage arranged for universal movement in a plane, a thermal instrumentality supported from said carriage, a shaft scribed, n carri'a raisin-g said shaft. I y Y of the character described,

formsupported from saidu'carriage onan his normal to said plane for following the contour of a template, means for rotating said shaft, said shaft. being mounted f axial- -movement without interference wi said rotating means, and a hand lever pivoted to said carriage and "ha ving a member fast thereto: for. engaging-- said -.-3.- Ina machine of. the character .de-

' arranged for universal shaft to cause 'movement thereof. I I p movementin a P am, a thermal instrumenmay supported from said -c'arriage,-'a shaft supportedfrom "saidcarriage on an axis normal: to said plane for following the contour of a template, means for rotating'said shaft,said shaft being axially movable without interfering with said rotating means,

said shaft having a series of alternate annu lar recesses and ridges coaxial with the shaft, and a spur gear for meshing therewith for axiallymoving said shaft.

4. Ina machine of the character dein a horizontal plane, a thermal instu-ui'n'en-- tality supported from said carriage, a shaft supported from said carriage tin a vertical axis for following the ccontour of a template, means for rotatinfsaid shaft, said shaft being axially. movable without interfering with said rotating means, a weighted mem- ,bercarried by said shaft to urge the shaft. axiallv downward, and .means for axially 6. -.In apparatus 7 late having an ed e to be traced and a simi arly directed auxi iary edge adjacent thereto, a follower for said template m i j.

comprising a-main shaft havingla frame at;

one end a tracing. shaftfiournalled in said frame, and having a tracing portionfor enaging the tracing edge ofsaid template, a driving-shaftjournalled in said frame and edge, means for. rotating and main shaft,

and means coupling"said shafts for causing said eng ing'jportionsautomatically to'ro on the e gas of said tem late.

Y j 7. In apparatus of thee aracter'describei a fixed template having an ed e to be-traced 1 and'a similarly directed 'aux'i iary-"edge a'd jacent thereto, .a follower for said template comprising a main shaft having a frame at having afportionforgengagingsaid auxiliary I one end,'a. tracing shaft journalled in said frame and'having a traein portion forengaging the tracing edge 0 said template, a

25 9. .In a machine of the character described,

driving shaft journalled in. said frame and having a portion for engaging-said auxiliary" edge, means fori'rotatin said mainshait, the: axi'sIof said main sha 1:: being disposed between-theaxes: of said. (tracer and sdrivers shafts, an lmeansco'uplingz said shafts for causingsai engaging. portions: automati cally to roll on the. ed eslof said template.

.1 Y 8"; Ina machine 0ft e character described,-

' a carriage arranged-for universal movement .in a p1ane,a;blo.w torch supported fromsai'd carnage, a shaft supporte riage on an axis normalto-said plane for following thecontonr of a template,'means from said carfor rotating said shaft, a member non-rotatable with respect to the template and carried byqsaid shaft to urge the shaft axially toward the template, anda thrust bearing between said shaft and said member to permit of free rotation of the shaft with respectto:

said member.

acarriage arranged for universal movement in a plane, a blow torch supported fromsaid carriage,-ra shaft supported from said carriageon anaxisnormal to said plane for following the contour of a template, means for rotating said shaft, a member'non-rotatable with respect to'said template for urgin said shaft axia-ll toward the-template, an an anti-friction. caring for permitting free rotation ofsaid: shaft with respect'to said member.. I

10. In apparatus of the character de- :scribed, a template follower comprisin a of the tem late.v

Signed y me at Boston, Massachusetts,

this 9th day of Apr-$1924..

ADOLF KREBS. 

